Orochi

Weapon: Tiger Spirit

Assist: Positional Assist / Assistless / Flexible

Special: Glimmer / Ruptured Sky / Glacies 

Passive A: Sturdy Impact / Mirror Impact / Death Blow

Passive B: Lull Atk/Res / Special Spiral

Passive C: Fatal Smoke / Time’s Pulse / Smoke Skills / Joint Drive Atk / Flexible

Sacred Seal: Death Blow / Sturdy Blow / Atk/Def Solo / Quickened Pulse / Hardy Bearing

• Orochi’s exceptional Attack coupled with the additional firepower from her exclusive Tiger Spirit grant her great raw damage output, thus allowing her to excel when equipped with an offense-leaning build; her ability to apply the Panic debuff does also make her a potential option within the context of Aether Raids Defense. Since the focus here is maximizing damage, a +ATK IV is coveted over all else. 
• Specials with short cooldowns (namely, Glimmer, Ruptured Sky, and to a lesser extent Moonbow) are ideal for general gameplay, as Orochi can access them frequently and may even pair them with Special Spiral for more consistent OHKOs. Those aiming to use her within Infantry Pulse compositions in Aether Raids Defense, however, may get better mileage out of Glacies for maximum potency. 
• Sturdy Impact is Orochi’s A skill of choice here as it greatly offsets her weakness to physical threats — her most glaring counters — through a substantial +10 Defense and enemy follow-up denial while still padding her damage. Although not quite as useful due to her inherently high Resistance, Mirror Impact is also an option that pairs nicely if using Glacies. Death Blow is always a solid option as well to simply add to her Attack.
• Lull Atk/Res works excellently to push Orochi’s offensive ceiling higher, provide some assistance to her survivability, and break through enemy bonuses — something particularly useful given that Tiger Spirit does not apply Panic Smoke until after her first round of combat. If using her with short cooldown Specials, Special Spiral can be considered to ensure their activation on her first attack each combat after starting the chain. 
• Fatal Smoke — or a regular stat-targeting Smoke skill if unavailable or simply not looking to invest that much — are candidates to stack more debuffs on top of Panic from her PRF, making her initiations even more dangerous. Alternatively, Time’s Pulse can be taken to assist Orochi’s damage by hastening her Special activations, or Joint Drive Atk to stack more boosts to her specialty stat. 
• For her Sacred Seal, simple stat-boosting skills like Death Blow or Atk/Def Solo work great, or Quickened Pulse for a similar reason to Time’s Pulse. Hardy Bearing is an Aether Raids Defense-specific option that may be equipped to shut down Vantage strategies should they be a particular threat to your specific composition.

Weapon: Plegian Torch+ (+RES) / Amity Blooms+ (+RES) / Tiger Spirit

Assist: Positional Assist / Flexible

Special: Noontime / Sol / Iceberg

Passive A: Mirror Stance / Distant Def / Atk/Res Solo 

Passive B: Null C-Disrupt / Lull Atk/Res / Special Spiral / Quick Riposte

Passive C: Atk Smoke / Pulse Smoke / Joint Drive Atk / Flexible

Sacred Seal: Quick Riposte / Mirror Stance / Mystic Boost / Distant Def

• Orochi may also be specialized more defensively and have her kit center around her ability to soak magical damage by merit of her high Resistance; this is typically her best bet for those who wish to use her in Aether Raids Offense. Increasing her Attack is once again a good choice for more damage (and healing if using certain Specials), but investing in Resistance also works to directly reduce how much damage she takes.
• While her base Tiger Spirit certainly can be used here, Orochi does have some inheritable options that lend themselves much better to her intended playstyle here. 
  • In particular, Plegian Torch is notorious for its debuff enhancement effect: for every visible Attack or Resistance debuff applied on her foe, this weapon inflicts an equivalent in-combat debuff on that respective stat plus five. Assuming one can consistently apply such debuffs (via Smoke Skills or outside support), this weapon allows Orochi to massively bolster her damage and durability to much greater heights than otherwise possible.
  • Amity Blooms is another fantastic inheritable weapon that trades Plegian Torch’s sheer stat ceiling for consistent healing on each of Orochi’s attacks. Alongside a modest -5 Atk/Res debuff on her foe, this innate sustain is useful to impart Orochi some leeway in her Special and/or skill choices since she may focus more on enhancing damage rather than survivability this way. 
• Utilizing a healing Special helps mitigate incurred damage for more consistent tanking. Both Noontime and Sol are generally good choices, but one may outshine the other depending on certain circumstances: for instance, Noontime is preferred if Summer Hilda support is available to activate them on every counterattack, whereas Sol is better if using Special Spiral to maximize HP recovery. 
  • Using Amity Blooms and/or Mystic Boost in Orochi’s build may give enough healing such that she can use a normal Special like Iceberg, though. 
• Mirror Stance 3 is highly recommended for its simultaneous Attack/Resistance boost, but moreover its protection from enemy Specials through built-in Guard; her typical inability to avoid enemy follow-up attacks means that she otherwise has a higher chance of taking the brunt of potentially lethal activations. Distant Def and Atk/Res Solo are other A skills she can choose from as well. 
• Taking Null C-Disrupt as Orochi’s chosen B skill is a compelling route to ensure she can effectively counter Dazzling Staff wielders and the Flash debuff, as these can quickly neuter her combat effectiveness otherwise. For more stats, Lull Atk/Res is the way to go, and Special Spiral also works as previously mentioned if using Sol. 
• Smoke skills are a staple for defensively-inclined builds to debilitate incoming threats and tank them more easily. Atk Smoke or Res Smoke take precedence over other choices if using Plegian Torch, otherwise Pulse Smoke is excellent to shut down compositions reliant on certain Special activations. Joint Drives are always good filler for C slots to further pad stats. 
• Orochi is generally too slow to perform follow-up attacks on her own, so using Quick Riposte certainly helps her out in that respect — and using it as her Sacred Seal frees up her B slot for other powerful options that she cannot equip here. If using it as her B skill regardless (or if not using it at all), though, her Sacred Seal should either be Mystic Boost for additional healing and Wrathful Staff negation or a stat-booster like Mirror Stance.

Weapon: Tiger Spirit

Assist: Positional Assist / Flexible

Special: Blazing Special / Growing Special

Passive A: Life and Death / Heavy Blade 

Passive B: Special Spiral

Passive C: Time’s Pulse / Res Smoke / Savage Blow / Flexible

Sacred Seal: Heavy Blade / Quickened Pulse 

• This build shifts the focus back to Orochi’s offensive capacity, but hinges her performance on her ability to leverage AoE Specials to shred through her opponents. Such Specials can be consistently activated in every round of combat by combining Special Spiral and Heavy Blade (either as her A skill or Sacred Seal), but do note that there is some necessary setup beforehand to get the chain started.
• Since the damage calculation for AoE Specials involves visible stats only (which is what also makes a +ATK IV so important!), Life and Death makes for the premier A skill to use here as it gives Orochi the biggest boost to her actual Attack possible. 
  • That being said, Heavy Blade is also an option as an A skill to free up her Sacred Seal for something else like Hardy Bearing to work around Vantage or Quickened Pulse to make it easier to start the chain. 
• In a similar vein, taking Time’s Pulse as Orochi’s C skill works well to lessen the amount of initiations required to commence her Special Spiral chain, though it is a rather hefty investment. More accessible options include Res Smoke and Savage Blow to supplement her OHKO potential. 
• As for what AoE Special to actually equip, Blazing AoE Specials are generally preferred over Growing due to their higher damage modifier to secure consistent OHKOs. Blazing Wind and Blazing Light have the most typically useful ranges of those available.